"You enter a state of controlled passivity, you relax your grip and accept that even if your declared intention is to justify the ways of God to man, you might end up interesting your readers rather more in Satan"

This quote by Ian Mcewan is a tip to writers that even if they have a specific objective in mind, the result may be various than expected. He is suggesting that if an author's objective is to describe the methods of God to their readers, they might wind up being more interested in Satan instead. This is a tip to authors to be open up to the creative procedure and to not be too stiff in their expectations. It is necessary to enter a state of controlled passivity and to relax one's grip on the outcome. This enables the author to be open up to the imaginative procedure and to be ready to accept whatever result may come. By doing this, the writer can create something that is more intriguing and engaging for their readers.